That extra who fell asleep after his scene was over and he was supposed to be dead. Leonard Nimoy wrote in I Am Spock that his snoring perplexed the sound engineers, who had no idea what might be causing such a peculiar noise...

From some of what he's said, he was actually thinking 'How obviously disinterested do I have to be before they'll sack me?' He'd asked for a better role, and then asked to leave, but they just held him to his contract and offered more money, so at one point he set out to get himself sacked. (According to his version at cons, that is).

I would disagree, Gates was great in the role of Doctor Crusher, but I must say Diana Muldaur was far worst Star Trek actor. Why in the world, they gave her a chance to replaced Gates McFadden during one season of TNG. Thank God, that they made agreement to bring back Gates after just one season with Diana Muldaur. Also, Diana appeared in one episode of TOS and she wasn't very good in that episode too, and that is when she was much younger.